EVERYDAY SCIENCE

Detailed explanation-1: -As air masses are pushed along by wind they may encounter mountains or other landforms. This confrontation forces the air mass to climb over the mountain. As the air increases in altitude it begins to cool, creating clouds. This can lead to rain, and if the temperature is low enough, snow.

Detailed explanation-2: -The orographic effect occurs when air masses are forced to flow over high topography. As air rises over mountains, it cools and water vapor condenses. As a result, it is common for rain to be concentrated on the windward side of mountains, and for rainfall to increase with elevation in the direction of storm tracks.

Detailed explanation-3: -In the same way, changes in relative humidity occur when warm moist air is forced to rise or, conversely, when cool dry air descends. For example, when an air mass moves over mountains, it cools as it rises, and when it reaches the dewpoint, water will condense.

Detailed explanation-4: -In regions of low pressure, air generally moves upward and cools, leading to condensation of water vapor, clouds, and precipitation. In regions of high pressure, air generally moves downward and warms, leading to drying and clear skies.

Detailed explanation-5: -Maritime air masses form over water and are humid. Continental air masses form over land and are dry. Therefore, an air mass that develops over northern Canada is called a continental polar air mass and is cold and dry. One that forms over the Indian Ocean is called a maritime tropical air mass and is warm and humid.